The present invention relates to a heated wiper system for use with the windshield wiper assembly of a vehicle.
In colder climates, the build up of ice on vehicle windshield wiper blades is a common problem. The ice causes the wiper blades to operate poorly which is an annoyance to drivers and can become a significant road hazard if the visibility of the driver through the windshield is significantly reduced.
Various wiper heating devices have attempted to overcome the problem of ice build up on wiper blades by mounting a heating element in close proximity to or directly in engagement with the wiper blades. In order for the heating element to operate effectively it is generally required that the heating element directly engage the wiper. Known heating devices however generally mount the heating element integrally within the wiper or wiper blade such that replacement of the wipers requires replacement of the heating element or portions thereof. The periodical replacement of the wipers can thus be expensive and requires time consuming assembly.
U.S. Pat. No. 6,028,291 to Heisler and U.S. Pat. No. 4,497,083 to Nielsen each provide a heated windshield wiper system in which a heater element extends through the resilient wiper element of a wiper blade. In each instance a releasable connector supplies power to the heating element at one end of the resilient wiper element permitting the heating element and wiper element to be replaced without replacement of the entire wiper blade. In the event that the wiper blade requires replacement however considerable rewiring of the heating element is required. Heisler in particular provides a thermostat mounted on the wiper blade in a location requiring replacement of the electrical supply wiring in the event that the thermostat fails and requires replacement.
U.S. Pat. No. 3,408,678 to Linker provides a windshield wiper assembly in which a heating element extends along the resilient wiper element. The electrical supply wiring to the heating element includes selective couplings at a location where the wiper blade mounts on a supporting wiper arm such that the entire blade including the heating element can be replaced. The heating element and selectively coupling in this instance however are required to be formed integrally with the wiper blade and therefore do not permit independent replacement of the various components of the wiper assembly.
According to one aspect of the present invention there is provided a heated wiper system for mounting on a wiper arm of a wiper assembly of a vehicle, the system comprising:
a wiper blade arranged to be selectively mounted on a free end of the wiper arm, the wiper blade including a resilient wiper element having a passage extending through the wiper element in a longitudinal direction of the wiper element from an opening at one end of the wiper element;
a heating element arranged to be received within the passage extending through the wiper element;
an electrical supply arranged to supply electrical power to the heating element;
a thermostatic sensor arranged to activate the heating element in response to a prescribed temperature condition; and
a selective connector arranged to selectively connect the heating element to the electrical supply;
the thermostatic sensor being coupled between the heating element and the selective connector so as to be selectively separable from the electrical supply with the heating element upon releasing the selective connector.
The particular arrangement wherein the thermostatic sensor is provided on the wiper blade between the selective connector to the electrical power supply and the heating element permits the thermostatic sensor and the heating element to be replaced together if required without the need to replace wiring of the electrical supply. Permitting the heating element to be slidably removed from the wiper element and selectively mounting the thermostatic sensor can be arranged to permit independent replacement thereof. The selective connectors located between the wiper blade and the electrical supply of the system enables the system to be assembled as a kit of parts permitting wipers of different length to be readily assembled within the same kit. This is particularly useful in accommodating many newer conventional automobiles in which the windshield wipers of the left and right sides of the vehicle are commonly of different lengths.
The heating element is preferably slidably mounted within the passageway with the thermostatic sensor being selectively mounted on the wiper blade such that the heating element and the thermostatic sensor are arranged to be selectively separable from the wiper blade upon release of the selective connector.
The selective connector is preferably arranged to be located adjacent the free end of the wiper arm when the wiper blade is mounted on the wiper arm with the selective connector being arranged to be released independently of the wiper blade from the wiper arm.
The connector is preferably arranged to be movable between a connected position in which the heating element and the thermostatic sensor are coupled to the electrical supply and a released position in which the heating element and the thermostatic sensor are released from the electrical supply for replacement thereof.
The resilient wiper element is formed of silicone rubber so as to resist damage from excessive heat produced by the heating element.
In a wiper assembly having two wiper arms, the system preferably comprises two wiper blades arranged to be mounted on the wiper arms respectively, each having a wiper element with a heating element mounted therein, the heating elements having a length which corresponds to the length of the respective wiper element regardless of the wiper elements being different in length.
When the heating elements are of different length, a longest one of the heating elements preferably has a lower electrical resistance per unit length thereof than a shortest one of the heating elements. Total electrical resistances of the respective two heating elements may thus be substantially equal.
According to a second aspect of the present invention there is provided a heated wiper system for mounting on the wiper arms of a wiper assembly of a vehicle, the system comprising:
a wiper blade arranged to be selectively mounted on a free end of each wiper arm, the wiper blade including a resilient wiper element having a passage extending through the wiper element in a longitudinal direction of the wiper element from an opening at one end of the wiper element;
a heating element arranged to be received within the passage extending through each wiper element;
an electrical supply arranged to supply electrical power to the heating elements;
a thermostatic sensor associated with each heating element and being arranged to activate the associated heating element in response to a prescribed temperature condition; and
a selective connector arranged to selectively connect each heating element to the electrical supply;
the heating elements having different lengths corresponding to different lengths of the wiper elements.
Each heating element preferably extends through the respective wiper element substantially a full length of the wiper element.